This year's flu season started early, and has hit the US with a vengeance. But does that make it an epidemic, or is the media hyping it up? Certainly it is nothing like the 2009 Swine flu pandemic, which killed 302 people around the world. Are infectious diseases like different strains of influenza becoming more deadly to humans?
The Centers for Disease Control and Prevention (CDC) say we are looking at the worst flu outbreak in 10 years, and just recently, the mayor of Boston declared a health emergency over the number of flu cases (700) and deaths (18) they have in that state.
The demographic transition theory tells us that as societies become more developed, their death rates drop, particularly infant mortality. People live longer, and then fertility rates drop. Death rates drop, in part, due to the elimination of infectious diseases - mostly because of improved sanitation and public health. So far, demographers who developed and who use the theory have tracked societal development through four stages. The US and other developed nations are in stage 4, with low fertility, increased longevity, population older on average, chronic diseases playing a much more significant role than infectious diseases. Other counties, considered to be "rapidly developing," like China, Japan, and Korea, are moving though stage 3 very quickly into stage 4, which is why they are struggling to catch up to the aging of their populations.
What is not clear in this theory is what stage 5 or stage 6 will look like. I often wonder, especially in light of the history of the HIV/AIDS pandemic, and with the swine flu and avian flu pandemic scares of the past few years, and now watching this year's flu season here in the States, if stage 5 of the demographic transition will see a return of infectious diseases as a major influence on population health. Food for thought. Which I would write about some more, except that (speaking of food) it's way past time for lunch, and I still haven't eaten.
In the meantime, watch out for this year's flu; it's a mean one. Particularly for children and the elderly. Eighteen children have died of the flu so far this season. This type of statistic for the elderly is not reported by the CDC, although all four reported flu-related deaths in Boston have been among the elderly.
Here is some helpful information from the CDC on the 2012-2013 flu season.